1. Field of the Invention
This invention relates to an original scanning device for scanning an original, used in a copier, an image reader or the like, and more particularly, to a device which includes both a unit for scanning a fixed original and a unit for scanning a moving original.
2. Description of the Related Art
In a conventional original scanning device used in a copier or the like, an original is mounted on an original-mount glass, and the original is scanned by moving scanning means, comprising a lamp, a mirror and the like, provided below the original-mount glass relative to the original. In order to read an original without being restricted by the size of an original which, for example, is longer than the length of original-mount glass, devices have been developed in which an original scanning unit of a scrolling-reading-type for reading an original being conveyed is provided in addition to a scanning unit for reading an original mounted on the above-described original-mount glass.
In such a device, a light-transmitting window is in general provided along side of the original-mount glass so that light from the original scanned by the scrolling-reading original scanning unit is guided within the main body of the device through the light-transmitting window.
In the above-described conventional device, however, while leakage of light from the original-mount glass is prevented since a pressing plate for pressing an original in a stopped state is in general provided on the original-mount glass, light originated from within the device leaks from the light-transmitting window since no particular member is provided near the light-transmitting window, causing an adverse effect on a human operator.
Furthermore, since external light enters the device from the light-transmitting window, a photosensitive member for receiving image light corresponding to the original sometimes receives unnecessary light, accelerating deterioration of the photosensitive member.
In order to overcome the above-described problems, an approach has been considered in which a cover is provided at the portion of the light-transmitting window. However, the opening and closing operation of the cover greatly depends upon the user. Hence, the above-described problems still remain if the user forgets to close the cover. Accordingly, such an approach is insufficient for a complete solution of the problems.